Wrench having a locked adjustable position

ABSTRACT

An adjustment wrench is afforded in which the adjusted position is locked by a worm nut held in engagement, by a coil spring, with a nonrotatable key. The gear thread on the nut, when turned, will adjust the movable jaw when the nut is unseated from the key.

United States Patent [72] Inventor References Cited UNITED STATES PATENTS 2,596,266 5/1952 McEnroee....................

Barry W. Thompson 8007 S. Chappel Ave [21] AppltNo. 844,571 [22] Filed Chicago, Ill. 60617 July24,1969 2,733,626 2/1956 Meso edec [45] Pa'emed 2,719,449 10/1955 Johnson.......................

Primary Exa ninerJames L Jones, Jr. 54 WRENCH HAVING A LOCKED ADJUSTABLE Attorney-K1111", & Zwke" POSITION ABSTRACT: An adjustment wrench is afforded in which the adjusted position is locked by a worm nut held in engagement, by a coil spring, with a nonrotatable key. The gear thread on the nut, when turned, will adjust the movable jaw when the nut is unseated from the key.

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INVENTOR.

HARRY W. THOMPSON TORNEYS PATENTEU MAYZS 197i This invention relates to an adjustable wrench having relatively slidable jaws of the open end type, and wherein the adjusted position is maintained by a worm nut.

An adjustable wrench of the ordinary open end kind has relatively movable jaws ordinarily positioned by a worm nut. As is well known, the adjusted position is frequently lost, and while there have been proposals for locking the nut to hold the adjusted position, the arrangements, if feasible for manufacture, are complicated, many times unreliable and in any event quite expensive. US. Pat. No. 2,719,449, for example, is the closest prior art of which l am aware as pertinent to the present disclosure, but experience with the wrench reveals that constant use produces sufficient wear that the essential parts for holding the adjusted position (a spring and a sliding pin) become loose and inefficient. This is possibly due to wear engendered by the type of pin movement and lock involved.

recess 26 which is shaped complemental thereto. The insert 27 is formed throughout its axis with an opening 28 which receives the upper end of the shaft extension 25. A radial The primary object of the present invention is to interpose a lock in an adjustable wrench in such a fashion that both reliability and inexpensive manufacture are assured. A further object of the present invention is to so construct an adjustable wrench as to enable the'fingers of one hand to both adjust the wrench and to set the lock.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawing which, by way of illustration, shows a preferred embodiment of the present invention and the principle thereof and what is now considered to be the best mode contemplated for applying that principle. Other embodiments of the invention embodying the same or equivalent principle may be made as desired by those skilled in the art without departing from the present invention.

In the drawing:

FIG. 1 is a fragmentary plan view of'an adjustable wrench constructed in accordance with the present invention and showing the essential parts thereof;

FIG. 2 is a fragmentary sectional view of a subassembly;

FIG. 3 is a detail ofthe locknut;

FIG. 4 is an end view of the locknut on the line 4-4 of FIG.

FIG. 5 is a sectional view on the line 55 of FIG. 6

FIG. 6 is an end view of a cup for housing a spring;

FIG. 7 is a plan view ofa key;

FIG. 8 is a perspective view of an insert; and

FIG. 9 is a fragmentary detail ofa modification.

The open end adjustable wrench 10 of the present invention, FIG. 1, includes relatively slidable jaws of which one jaw, 11, may be considered the fixed jaw and the other jaw 12 the movable jaw, the usual land and groove 15 being provided between the jaws for. guiding the two slidably in the course of adjustment.

The movable jaw 12 is provided with the usual gear rack 16 which features in adjustment as will be explained. The fixed jaw 11 includes a relatively large recess 17 in which is housed an adjusting nut 18 having a worm gear thread 20 meshed with the teeth of the rack 16. The recess is much longer than the nut in an axial sense for reasons to be explained.

In order to lock the nut in a fixed position characterizing the set dimension of the wrench jaws, the nut is held against rotation by a key, and specifically in the present instance, in the preferred embodiment of the invention, the key is in the form ofa long shaft 21, FIG. 7, having a plurality of flat lands 22 at the key end.

The key shaft 21 fits slidably in a recess 23, FIG. 1, formed in the lower part of the fixed jaw. The recess 23 is coaxial with the recess 17, and the recess 23 is polygonal in cross section so that the key lands 22 fit complementally therein. Thus the key 23 is nonrotatably seated in the fixed jaw.

The shaft 21 includes a reduced extension 25, and when the shaft 21 is in place the extension 25 axially spans the recess 17 and further extends into a large recess 26 formed in the upper side of the fixed jaw 11. An insert 27, FIGS. 1 and 8, of polygonal shape in cross section is fitted nonrotatably in the opening 29 is formed in the insert 27, and a corresponding opening is formed in the fixed jaw 11 and shaft 21 to receive a press fit pin 30 which snugly fits the opening 29 in the insert whereby the shaft 21 may be locked in place against axial displacement. The pin 29, when an appropriate punch is applied thereto, may be removed to enable the shaft to be disassembled.

As shown in FIG. 1 the key lands 22 extend a distance x axially into the recess 17, and the nut 18 in the lower portion, FIG. 2, is broached witha key seat 18A which fits the key 22, whereby the worm nut 18 is locked against rotation. Preferably, the key lands 22 are large in number so that there may be minute adjustment for reasons apparent from the description to follow.

The worm nut 18 is counterbored at 188 coaxial with the key seat 18A. A spring retainer sleeve 35 of cuplike shape, FIG. 5, is set in the counterbore 18B of the worm nut, and the bottom of the cuphas an opening 36 through which .extends the reduced portion 25 of the shaft 21. The opposite end of the sleeve 35 has lugs or ears extending therefrom, and these lugs are so dimensioned and configured as to engage opposed flat sides of the recess 26 in the upper side of the fixed jaw 11, thereby securing the cup 35 against rotation. The cup may be a screw machine part made from hex stock or could be a part produced in a punch press. V

A coil spring 40, FIG. 1, is set in the cup 35 and concentrically surrounds the shaft extension 25 whereby the latter serves as a guide for the spring. The upper end of the spring engages the insert 27 so that the latter also serves as a spring stop. The insert 27 may be counterbored to form a seat for the spring. The lower end of the spring bears on the bottom of the cup, and hence the coil spring 40 serves to apply pressure to the nut, through the cup, sufficient to hold the nut normally on the key 22, thereby maintaining the wrench jaws in a locked position. It will be observed that the flanges or ears 37 of the cup are displaced axially from the spring stop 27 by a fraction of an inch y greater than the distance x.

When it is desired to adjust the wrench jaws the mechanic uses his thumb to displace the worm 18 from the key, moving the worm through the distance x. The movable jaw is carried along. Inasmuch as the worm is now free of the key, the worm may be turned by ones thumb to appropriately position the movable jaw, and when the adjusted position has been attained, the pressure of the mechanics thumb is removed allowing the spring to reseat the worm nut on the key 22, establishing the lock. Quite naturally, as in the instance of any wrench or plier-vice constructed for locking in adjusted position, some trial and error is involved for the last fraction of adjustment, and in this connection it is advantageous to have a key with numerous lands 22 so that very little rotation of the nut is required to produce mating of the key and the key seat of the nut. The x distance mentioned above will vary with the size of the wrench.

The spring retainer sleeve 35 not only houses the spring to avoid damage thereto, it also prevents the coils of the spring from being twisted when the nut is turned. Thus with the sleeve 35 anchored against rotation as it is, the sleeve will not turn when the nut is turned and therefore the spring will not be turned. Nonetheless the means for avoiding twisting of the coil springs may take other forms, as for example a pair of antifriction washers at the opposed ends of the spring, one between the lower end of the spring and the counterbore in the nut, and one between the upper end of the spring and the spring stop. In this event the sleeve 35 may be dispensed with although this would be at the sacrifice of losing the protective spring housmg.

Other modifications are possible insofar as concerns retention of the shaft 21 and the stop for the spring since it is only essential that some-means be provided to hold shaft 21 in place and that there be some means to confine the spring so that it will be compressed when the nut is unseated from the key.

Likewise the form and shape of the cup may be varied, under the present invention, and the principle of the present invention is not limited in this regard. For example, the cup could have the form 35A shown in FIG. 9, and a shortened spring 40A is used therewith, the lower end of the spring seating in a counterbore seat 35B at the upper end of the cup. The upper end of the spring 40A would engage the stop 27 as above described.

Further, as shown in FIG. 9, the nut may be a ratchet nut 45, modified at its lower end to present ratchet teeth 4ST engaged with related teeth in a ratchet disc 50, the latter having a seat press fitted to the key 22, and it may also be pinned to the key so as to be part of the key in either event. The ratchet teeth be so sloped in relation to the thread of the nut as to enable the nut to be turned freely in one direction, but held against rotation in the opposite direction. The nut, FIG. 9, may be slipped off the key disc 50 for the purpose above described, and as in' the foregoing embodiment spring pressure normally holds the nut on the key seat represented by the ratchet disc. MOdifications and alterations may therefore be made without departing from the principle of the present invention as claimed.

I claim:

1. In an adjustable wrench having relatively slidable jaws of which the movable one is provided with a gear rack, the other jaw having a recess therein, a worm nut'located in the recess of said other jaw and having a worm gear thereon meshed with the teeth of the rack, the recess being much longer in an axial sense than the length of the nut, means affording a key engaged with a seat on the nut to prevent rotation of the nut, and

a spring applying axial pressure to 'and normally holding the nut seated on the key, said nut and the movable jaw being manually movable in unison axially against the spring to unseat the nut from the key whereby manual rotation of the nut drives the rack to appropriately position the movable jaw, the spring serving to return the nut to its normal position when the nut is released.

2. A wrench according to claim 1 wherein the key is formed on one end of a shaft, said key itself having a portion secured nonrotatably in a complemental seat in the jaw having the recess, the spring being a coil spring, and the shaft including an extension extending through the nut to serve as a guide for the spring which concentrically surrounds said extension of the shaft.

3. A wrench according to claim 2 wherein a spring stop is fitted nonrotatably in said other jaw and being in engagement withthe end of the spring opposite the end in the cup.

4. A wrench according to claim 3 wherein the shaft is secured against displacement by a pin joining the shaft and the spring stop.

5. A wrench according to claim 4 wherein means is afforded to prevent the coils of the spring from twisting when the nut is rotated.

6. A wrench according to claim 5 wherein the spring is freely housed in acuplike sleeve nested in a recess in the nut with the end of the spring opposite the stop bearing on the bottom of the sleeve to apply pressure through the cup to the nut, and means holding the sleeve against rotation at all times thereby to prevent twisting of the spring coils when the nut is rotated, 

1. In an adjustable wrench having relatively slidable jaws of which the movable one is provided with a gear rack, the other jaw having a recess therein, a worm nut located in the recess of said other jaw and having a worm gear thereon meshed with the teeth of the rack, the recess being much longer in an axial sense than the length of the nut, means affording a key engaged with a seat on the nut to prevent rotation of the nut, and a spring applying axial pressure to and normally holding the nut seated on the key, said nut and the movable jaw being manually movable in unison axially against the spring to unseat the nut from the key whereby manual rotation of the nut drives the rack to appropriately position the movable jaw, the spring serving to return the nut to its normal position when the nut is released.
 2. A wrench according to claim 1 wherein the key is formed on one end of a shaft, said key itself having a portion secured nonrotatably in a complemental seat in the jaw having the recess, the spring being a coil spring, and the shaft including an extension extending through the nut to serve as a guide for the spring which concentrically surrounds said extension of the shaft.
 3. A wrench according to claim 2 wherein a spring stop is fitted nonrotatably in said other jaw and being in engagement with the end of the spring opposite the end in the cup.
 4. A wrench according to claim 3 wherein the shaft is secured against displacement by a pin joining the shaft and the spring stop.
 5. A wrench according to claim 4 wherein means is afforded to prevent the coils of the spring from twisting when the nut is rotated.
 6. A wrench according to claim 5 wherein the spring is freely housed in a cuplike sleeve nested in a recess in the nut with the end of the spring opposite the stop bearing on the bottom of the sleeve to apply pressure through the cup to the nut, and means holding the sleeve against rotation at all times thereby to prevent twisting of the spring coils when the nut is rotated. 